506 DISEASES OF THE HORSE. 



The local symptoms are those of pain, especially to pressure on side 

 of the flanks and belly; distention of the latter, and sometimes the 

 formation of flatus, or gas, and constipation. 



Other occasional complications are nephritis, hepatitis, inflamma- 

 tion of the flexor tendons and rupture of them, and abscesses. 



Diagnosis. — The diagnosis of influenza is based upon continued 

 fever, with great depression and symptoms of stupor and coma ; the 

 rapidly developing, dark-saffron, ocher, yellowish discoloration of the 

 mucous membranes, swelling of the legs and soft tissues of the geni- 

 tals. Wlien these symptoms have become manifested the diagnosis 

 of a local complication is based upon the same symptoms that are 

 produced in the local diseases from other causes, but in influenza 

 the local symptoms are frequently masked or even entirely hidden 

 by the intense stupor of the animal, which renders it insensible to 

 pain. The evidence of colic and congestion, which is followed by 

 diarrhea, indicates enteritis. The rapid breathing or difficulty of 

 respiration points to a complication of the lungs, but, as we have 

 seen in the study of the symptoms, the local evidences of lung lesions 

 are frequently hidden. Again, we have seen that inflammation of 

 the feet, or founder, complicating influenza is frequently not shown 

 on account of the insensibility to pain on the part of the animal, 

 which indicates the importance of running the hand daily over the 

 hoofs to detect any sudden elevation of temperature on their surface. 



The diagnosis of brain trouble is based upon the excessive violence 

 which occurs in the course of the disease, for during the intervening 

 period or coma there is no means of determining that it is due to this 

 comj)lication. Severe cases of influenza may simulate anthrax in the 

 horse. In both we have stupor, the intense coloration of the mucous 

 membranes of the eyes, and a certain amount of swelling of the legs 

 and under surface of the belly. The diagnosis here can be made only 

 by microscopic examination of the blood. In strangles, equine variola, 

 and scalma we have an intense red, rosy coloration of the mucous 

 membranes, full, tense pulse, and, although in these diseases we may 

 have depression, we do not have the stupor and coma except in severe 

 cases which have lasted for some days. In influenza we have no evi- 

 dence of the formation of pus on the mucous membranes as in the 

 other diseases, except sometimes in the conjunctivae of the eyes. 



In severe pneumonia (lung fever) we may find profound coma, 

 dark yellowish coloration of the mucous membranes, and swelling of 

 the under surface of the belly and legs ; but in j^neumonia we have the 

 history of the difficulty of breathing and an acute fever of a sthenic 

 type from the outset, and the other symptoms do not occur for sev- 

 eral days; while in influenza we have the history of characteristic 

 symptoms for several days before the rapid breathing and difficulty 

 of respiration indicate the appearance of the complication. Without 



